Total Synthesis and Revision of C6 Stereochemistry of (+)-Amphidinolide W
作者:Arun K. Ghosh、Gangli Gong
DOI:10.1021/jo052181z
日期:2006.2.1
An enantioselective first totalsynthesis and structural revision of the cytotoxic natural product amphidinolide W is described. We initially investigated a ring-closingmetathesisbased synthetic strategy to form the 12-membered macrocycle. This strategy was unsuccessful as it led to formation of a 17-membered macrocycle. Subsequently, we explored an alternative strategy that involved cross-metathesis
0-functional groups at adjacent positions to the corresponding propargylic ethers was successfully carried out under the DBU conditions through 2-bromo-1-alkenes as intermediates. The optically active γ-lactone-class natural products, such as (-)-muricatacin (4) and (R,R)-sapinofuranone B (5) were synthesized using the propargylic ether intermediate produced by the elimination reaction mentioned above.
Synthesis of Nonadjacently Linked Tetrahydrofurans: An Iodoetherification and Olefin Metathesis Approach
作者:Lei Zhu、David R. Mootoo
DOI:10.1021/ol0352761
日期:2003.9.1
[reaction: see text] A convergent approach to the synthesis of the bis-tetrahydrofuran (THF) components of the nonadjacently linked THF-containing acetogenins is illustrated in the synthesis of 2, a potential intermediate for the antitumor agent bullatanocin (squamostatin C). The plan centers on the olefin cross-metathesis of THF allylic alcohol derivatives 3 and 4 as the key segment coupling step